porting findutils testing to use uutests

Cargo.toml

@@ -19,6 +19,8 @@ onig = { version = "6.4", default-features = false }
 uucore = { version = "0.0.30", features = ["entries", "fs", "fsext", "mode"] }
 nix = { version = "0.29", features = ["fs", "user"] }
 argmax = "0.3.1"
+uutests = { version = "0.0.30" }
+ctor = "0.4.1"
 
 [dev-dependencies]
 assert_cmd = "2"

tests/common/mod.rs

@@ -8,3 +8,13 @@
 // in one test but not another can cause a dead code warning.
 #[allow(dead_code)]
 pub mod test_helpers;
+pub const TESTS_BINARY: &str = env!("CARGO_BIN_EXE_find");
+
+// Use the ctor attribute to run this function before any tests
+#[ctor::ctor]
+fn init() {
+    unsafe {
+        // Necessary for uutests to be able to find the binary
+        std::env::set_var("UUTESTS_BINARY_PATH", TESTS_BINARY);
+    }
+}

tests/find_cmd_tests.rs

@@ -16,6 +16,8 @@ use std::fs::{self, File};
 use std::io::{Read, Write};
 use std::{env, io::ErrorKind};
 use tempfile::Builder;
+use uutests::util::TestScenario;
+use uutests::{at_and_ucmd, new_ucmd, util_name};
 
 #[cfg(unix)]
 use std::os::unix::fs::symlink;
@@ -39,15 +41,14 @@ fn fix_up_regex_slashes(re: &str) -> String {
     re.to_owned()
 }
 
-#[serial(working_dir)]
 #[test]
 fn no_args() {
-    Command::cargo_bin("find")
-        .expect("found binary")
-        .assert()
-        .success()
-        .stderr(predicate::str::is_empty())
-        .stdout(predicate::str::contains("test_data"));
+    let ts = TestScenario::new("find");
+    ts.cmd(env!("CARGO_BIN_EXE_find"))
+        .current_dir(env!("CARGO_MANIFEST_DIR"))
+        .succeeds()
+        .no_stderr()
+        .stdout_contains("test_data");
 }
 
 #[serial(working_dir)]
@@ -707,15 +708,13 @@ fn find_time() {
 
 #[test]
 fn expression_empty_parentheses() {
-    Command::cargo_bin("find")
-        .expect("found binary")
-        .args(["-true", "(", ")"])
-        .assert()
-        .failure()
-        .stderr(predicate::str::contains(
-            "empty parentheses are not allowed",
-        ))
-        .stdout(predicate::str::is_empty());
+    let (_at, mut ucmd) = at_and_ucmd!();
+    ucmd.arg("-true")
+        .arg("(")
+        .arg(")")
+        .fails()
+        .stderr_contains("empty parentheses are not allowed")
+        .no_stdout();
 }
 
 #[test]